In spite of the large number of repositioned drugs and direct-acting antivirals in clinical trials for the management of the ongoing COVID-19 pandemic, there are few cost-effective therapeutic options for severe acute respiratory syndrome (SARS) coronavirus 2 (SCoV2) infection. In this paper, we show that xanthorrhizol (XNT), a bisabolane-type sesquiterpenoid compound isolated from the Curcuma xanthorrhizza Roxb., a ginger-line plant of the family Zingiberaceae, displays a potent antiviral efficacy in vitro against SCoV2 and other related coronaviruses, including SARS-CoV-1 (SCoV1) and a common cold-causing human coronavirus. XNT reduced infectious SCoV2 titer by ~3-log10 at 20 µM and interfered with the replication of the SCoV1 subgenomic replicon, while it had no significant antiviral effects against hepatitis C virus and noroviruses. Further, XNT exerted similar antiviral functions against SCoV2 variants, such as a GH clade strain and a delta strain currently predominant worldwide. Neither SCoV2 entry into cells nor the enzymatic activity of viral RNA polymerase (Nsp12), RNA helicase (Nsp13), or the 3CL main protease (Nsp5) was inhibited by XNT. While its CoV replication inhibitory mechanism remains elusive, our results demonstrate that the traditional folk medicine XNT could be a promising antiviral candidate that inhibits a broad range of SCoV2 variants of concern and other related CoVs.
|Publication status||Published - 2021 Nov|
Bibliographical noteFunding Information:
Funding: This work was supported by the National Research Foundation of Korea (NRF) grants (NRF 2020M3E9A1041759 and 2020R1A2C2005170 to J.-W.O.; NRF 2019R1A6A1A03032869 to J.-S.S.) funded by the Ministry of Science and ICT (MIST), South Korea, and in part by the Brain Korea 21 (BK21) FOUR program (to J.-W.O.) and the BK21 FOUR program for Medical Science (to J.-S.S.). H.C. was supported by a postdoctoral fellowship from the Brain Korea 21 (BK21) FOUR program.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
All Science Journal Classification (ASJC) codes
- Medicine (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)